Paul Components Melvin Chain Tensioner. Converts frames for single speed use. Long enough for a Dingle-setup, (2 rings, one cog) 20T max. - The Melvin uses two pulleys, just like a rear derailleur, which gives it 20 teeth of chain wrap - Will work with multiple front chain rings while maintaining proper chain tension - The pulleys are made of extruded and machined aluminum and have sealed bearings for durability - Pulleys are 2.25mm thick at the tooth which fits inside most narrow 6 through 9 speed chains, and the pulley cage is wide enough to allow 1/8? single speed chains as well - Long enough for a Dingle-setup, (2 rings, one cog) 20T max - Do not use with a coaster brake or fixed gear - Includes Paul's own Sealed Bearing Pulleys

SRAM's Force WiFli Rear derailleur is made for wide-range 2x10 systems. Its long cage can handle an 11-32 cassette! You get the huge gear range of a triple with reduced weight and better shifting. Of course, the WiFli still uses SRAM's renowned Exact Actuation technology for precision shifts every time. Plus, the Force is crafted with cutting-edge materials, such as a super-light carbon cage and a magnesium inner link for feathery low weight, flawless shifting and reliability.

Leveraging the legendary history of SRAM shifting, the GX 2x11 rear derailleur provides incredible shifting speed and precision. X-Actuation technology eliminates slop and shifting variation while SRAM's roller bearing clutch technology delivers maximum drivetrain stability—even through the most punishing terrain. And with SRAM's Cage Lock, wheel removal and installation are easier than ever. • X-Actuation for precise and dependable 11-speed performance • Focused chassis design for all conditions and usage • 10-42-tooth wide range cassette compatible

Shimano Side Swing front derailleurs feature improved cable routing for smooth and efficient front shifting effort and increased clearance for larger tires and shorter chainstays. - Optimal front system for internal cable routing - Enhanced maneuverability with plus-sized tires - Increased shifting efficiency and light and smooth operation force - D, E, M type mounts are available - M type mount requires 34.9mm adapter

Incredibly fast, astonishingly quiet, and impressively precise — fly through all 11 gears with SRAM's Force 22 WiFLi Rear Derailleur. It takes advantage of SRAM's Exact Actuation technology for precision shifts every time. Carefully shaped jockey wheels work together with the sculpted cage for lightning-fast, ultra-precise shifts, and an elastomer coating applied to the jockey wheels makes for extra quiet operation. A carbon outer cage, aluminum inner cage, and magnesium inner link keep the Force 22 WiFLi at a svelte 190 grams. The WiFli version shifts up to a 32T max cog for a super-wide gear range.

The SRAM RED front derailleur, thanks to Yaw technology, changes everything, eliminating the need for shifter trim. Instead of simply moving back and forth, the derailleur cage actually rotates to maintain a consistent angular relationship with the chain. As a result, shifts feel more direct and precise. Combined with the SRAM RED crankset and X-GlideR chainrings, it delivers an unmatched performance advantage in front shifting. - SRAM Road 11-speed compatible - Yaw Technology - Slim spring design eliminates frame interference - Optimized for shifting with X-GlideR chainrings - Precision install markings - Integrated chain spotter protects your frame without adding any extra clunk and adjusts independently of the derailleur itself - Speeds: 2x11 - Material: Aluminum outer cage, Tool steel inner cage, Composite tail - Weight: 69g (braze-on), Chain spotter: 10.2 grams - Outer Cage: Aluminum - Compatibility: SRAM RED 22 & Force 22 Front Shift-Brake levers & X-GlideR Chainrings, SRAM R2C Aero SL-1190 shifters, SRAM R2C Aero SL-1150 shifters, SRAM 900 Aero brake levers, SRAM 500 Aero brake levers - Inner Cage: Tool steel

The SRAM Rival 1 X-Horizon rear derailleur is engineered for smooth, reliable shifting action—from the larger upper pulley offset to the 12-tooth X-Sync pulley wheels. By eliminating unwanted chain movement, X-Horizon shifts faster, puts an end to ghost shifting, and reduces shift force and chain slap. And with Cage Lock technology, wheel removal and installation are easier than ever. • X-Horizon design reduces shift force while eliminating ghost shifting and chain slap • 12-tooth X-Sync pulley wheels • Large upper pulley offset automatically adjusts chain gap • Sealed cartridge bearings Aluminum cage • Technologies: X-Horizon, Exact Actuation, X-Sync, Roller Bearing Clutch, Cage Lock • Medium cage: 11-26 through 11-36 cassettes • Long cage: 10-42 cassette

The Shimano Deore XT RD-M8100/M8120 rear derailleur is designed to provide smooth and stable shifting for 12-speed MTB drivetrains. - Offers fast and shockless shifting - The low-profile design includes a bumper added to the derailleur pulley cage - Shimano Shadow RD+ technology reduces chain slap and creates a quieter drivetrain - Includes large, 13T pulley - Long cage is designed to be used with 1x12 drivetrain systems - Rear Derailleur Mount Type: Shimano Rear Direct Mount, 10x1 Standard - Drivetrain Speeds: 12 - Cage Length: Long - Chain Wrap Capacity (teeth): 41 teeth - Largest Cog: 51 - Weight: 284 g - Rear Der/Shifter Compatibility: Shimano Mountain

With an integrated chain stabilizer mechanism, the Shimano GRX derailleur provides a quieter experience while delivering shifting security and precision on mixed terrain. For rides on smooth surfaces, the derailleur features an ON/OFF switch for the chain stabilizer. The RD-RX810 rear derailleur is compatible with road cassettes with a max cog size of 34T. - Adjustable, gravel-tuned chain stabilizer prevents chain slapping and drops - Switch stabilizer ON/OFF to match the terrain - Silent and uninterrupted rear shifting on rough terrain - Low cog: Max. 34T/Min. 30T - High cog: Max. 11T/Min. 11T - Total capacity: 40T - Compatible with current road Dual Control Lever - Maximum front chainring range: 17T

Ultegra RX brings Shimano's pioneering chain stabilizing technology to road cycling, delivering smooth and precise shifting over technical terrain. It expands road bike capabilities, inspiring confidence on any surface and drives the evolution of road cycling to include greater elements of adventure. No longer is the road bike narrowly defined. Shimano Ultegra RX broadens the notion of drop bar riding and emboldens cyclist to explore further. - Chain Stabilizer mechanism adopted from MTB design - Stabilizer ON/OFF switch - Compatible with current road dual control lever - Shadow RD technology - Direct mount compatible - Maximum cog size: 34t - Total capacity: 39t

The SRAM Rival 1 rear derailleur is engineered for smooth, reliable shifting action, delivering 100% of what you demand. By eliminating unwanted chain movement, X-HORIZON shifts faster, reducing shift effort and chain slap. - X-HORIZON design reduces shift force while eliminating ghost shifting and chain slap - Large upper pulley offset automatically adjusts chain gap - Sealed cartridge bearings and aluminum cage - Technologies: X-HORIZON, EXACT ACTUATION, X-SYNC, ROLLER BEARING CLUTCH, Cage Lock - Medium cage: 11-26 through 11-36 cassettes, 269g - Long cage: 10-42 cassette, 275 g

Campagnolo's Veloce Rear Derailleur uses an advanced-parallelogram design that assures precise and quick shifting. The aluminum construction reduces weight and boosts strength for crisp gear changes. Plus, the pulleys are made from a special material that renders the drivetrain nearly silent.

Incredibly fast, buttery smooth and impressively precise gear changes are here with SRAM's Force Rear Derailleur. It takes advantage of SRAM's Exact Actuation technology for precision shifts every time. Plus, the Force is crafted with cutting-edge materials, such as a super-light carbon cage and a magnesium inner link for feathery low weight, flawless shifting and reliability.

Shimano's Deore XT Rear Derailleur uses cold-forged construction and cutting edge technology to deliver crisp shifting, real-world reliability, and trademark precision. Plus-type derailleurs use a lever-actuated clutch spring to prevent chain slap, reduce noise while on the trail, and improve chain engagement when riding over rough terrain. Sealed pulley bearings keep things spinning smoothly, and wide plate construction prevents the derailleur from getting clogged with mud and debris.

The rear derailleur is the defining component of the Centaur groupset. Inheriting many of the technologies used by Campagnolo’s top-of-the-range rear derailleurs, the Centaur offers shifting performance to meet all requirements – even professionals’. The new Campagnolo Centaur rear derailleur has been designed to be compatible with cassettes with up to 32 teeth. With the upper jockey wheel’s longer teeth, the lower wheel’s smoothed teeth, and a long list of performance-oriented technology, the Centaur rear derailleur is the top component in its class – and all at 15 grams lighter than its competitors. - Lightweight technopolymer upper and lower bodies reinforced with glass fiber for reduce weight and increased strength - Features the same shape of Super Record, offering similar shifting performance - Upper pulley wheel with longer teeth for easier rear shifting - Lower pulley wheel with chamfer teeth for increased smoothness - Pulley wheels with bushings - Drivetrain Speeds: 11 - Cage Length: Medium - Chain Wrap Capacity (teeth): 37 teeth - Rear Der/Shifter Compatibility: Campy Centaur/Potenza/Chorus/Record/Super Record 2015+ - Largest Cog: 32

Shimano's Deore XT Rear Derailleur uses cold-forged construction and cutting edge technology to deliver crisp shifting, real-world reliability, and trademark precision. Plus-type derailleurs use a lever-actuated clutch spring to prevent chain slap, reduce noise while on the trail, and improve chain engagement when riding over rough terrain. Sealed pulley bearings keep things spinning smoothly, and wide plate construction prevents the derailleur from getting clogged with mud and debris.

Incredibly fast, astonishingly quiet and impressively precise — fly through all 11 gears with SRAM's Force 22 Rear Derailleur. It takes advantage of SRAM's Exact Actuation technology for precision shifts every time. Carefully shaped jockey wheels work together with the sculpted chain pulley cage for lightning-fast, ultra-precise shifts, and an elastomer coating applied to the jockey wheels makes for extra quiet operation. A carbon outer cage, aluminum inner cage, and magnesium inner link keep the Force 22 at a svelte 178 grams.

Shimano Ultegra R8000 Shadow rear derailleur. - Sleek integrated appearance - Low-profile design - Race endurance - Optimized slant angle - Wide compatibility - Short cage covers: 11-25T to 11-30T - Medium cage covers: 11-28T to 11-34T - Model Number: RD-R8000 - Series: Ultegra - Maximum Sprocket: 30T - Minimum Sprocket: 11T - Maximum Front Difference: 16T - Average Weight: 200 grams (short cage type), 210 grams (medium cage type)

Incredibly fast, astonishingly quiet and impressively precise—fly through all 11 gears with SRAM's Rival 22 Rear Derailleur. It takes advantage of SRAM's Exact Actuation technology for precision shifts every time. Carefully shaped jockey wheels work together with the sculpted chain pulley cage for lightning-fast, ultra-precise shifts, and an elastomer coating applied to the jockey wheels makes for extra quiet operation. Aluminum inner and outer cages, aluminum links, and stainless steel hardware keep the durable Rival 22 at a svelte 191 grams. Plus, SRAM's WiFLi technology delivers a wider range of gears than your standard triple, faster shifts through two chainrings and every gear on the rear cassette, all with significant weight savings.

Shimano's Ultegra Rear Derailleur delivers category-defining 11-speed shifting. At the heart of the derailleur is a light, tough, cold-forged-aluminum body with a wide, rigid pivot design that maximizes shifting speed and equalizes shift effort across the cassette. Smooth-spinning pulleys use sealed bearing to keep out the dirt and ensure quiet running in the miles to come.

- Alloy cage with adjustable chain stabilizer - Forged alloy links - 14t lower pulley and 12t upper pulley - Max rear sprocket is 50t with 1X setup; 42t with 2X - 10/11/12 speed compatible (Shimano 10/11 speed & SRAM 12 speed)

The SRAM NX X-HORIZON rear derailleur provides the same smooth, reliable shifting action as XX1—from the larger upper pulley offset to the 12-tooth X-SYNC pulley wheels. By eliminating unwanted chain movement, X-HORIZON shifts faster, puts an end to ghost shifting and reduces shift force and chain slap. And with Cage Lock technology, wheel removal and installation are easier than ever. - X-HORIZON design that reduces shift force, ghost shifting and chain slap - 12-tooth X-SYNC pulley wheels - Fully compatible with all SRAM MTB 1x drivetrains - Most affordable fully featured 1x rear derailleur in the industry - Speeds: 11-speed - Weight: 322 grams - Color: Black - Compatibility: X-ACTUATION - Bearings: Steel - Cage Size: Long - Max Tooth: 42

The SX Eagle derailleur features the proven SRAM 1x-specific X-HORIZON design and easily facilitates 11-50T and 10-52T cassette capacity, providing quiet, consistent performance and durability. - X-SYNC pulley technology provides greater efficiency, crisper shifting, and quieter operation. - Cage Lock offers discovery-level riders easy trailside wheel removal.

Shimano's Deore Shadow+ Rear Derailleur is loaded with mountain bike technology. The Shadow design tucks the rear derailleur closer in to the wheel, reducing damage from rocks, roots, and trail obstacles. When it comes to gear changes, Shimano's Dyna-Sys supplies consistent, smooth shifting across the entire cassette. And the Shadow+ clutch maximizes chain control by virtually eliminating chain slap and excess noise with its integrated cage-tensioning clutch. - Medium Cage (for 2x10 drivetrains) - Long Cage (for 3x10 drivetrains) - For use with Shimano 10-speed drivetrains - High-efficiency drivetrain for aggressive trail riding - Optimized gear combinations and ratios for trail riding - Maximum chain wrap capacity: 41T (medium cage)/43T (long cage) - Largest cog: 42T (medium cage)/36T (long cage) - Compatible with wide range cassette - Silent and stable for technical trail riding - Improved stability and chain retention longevity - Light shifting effort - OPTISLICK cable - Smooth and precise shifting - DYNA-SYS compatible system

SRAM’s Apex 1 drivetrain provides the gear range and the shifting simplicity to let you simply go where you want. The Apex 1 rear derailleur makes that gearing choice a reality with clean, crisp shifts, thanks to SRAM’s X-Horizon geometry and their Roller Bearing Clutch. - X-Horizon design reduces shift force, eliminates ghost shifting and chain slap - Compatible with 10-speed and 11-speed SRAM 1x road systems - With Cage Lock technology, wheel removal and installation are easier than ever - Equipped with Roller Bearing Clutch - Large upper pulley offset automatically adjusts chain gap - Weight: 314 grams - Outer Cage: Steel - Compatibility: 10-speed and 11-speed SRAM 1x road systems - Inner Cage: Steel - Cage Size: Long - Max Tooth: 42t - Pulleys: Sealed cartridge bearings - Pull: Exact Actuation

The Box Three Rear Derailleur simplifies the features found on the Prime 9 Box One and Two rear derailleurs making for a fully featured wallet friendly rear derailleur. Including a Limited Slip Clutch, Sealed bearing pulleys and a solid construction Box Three Rear derailleurs are compatible with 11-46 and 11-50t derailleurs making it one of the most versatile derailleur offerings for Prime 9.

The SLX M7100 series of derailleurs deliver advanced shifting performance with decreased tension in the low gear position and an added bumper on the pulley cage. Larger 13T pulleys increase efficiency and chain management while compatibility with Shimano's new 12-speed cassettes boosts range. - Advanced shifting performance provides the confidence to enjoy any trail - Fast and shockless shifting - Hyperglide+ - Extra wide range 12-speed drivetrain -10-51T (12-speed) - Silent drivetrain in all gear positions - Decreased rear derailleur and chain tension in low gear - New bumper added to rear derailleur pulley cage - Bump Stopper - Bigger 13T pulley - Stable drivetrain on rough terrain - Low-profile design - Shimano Shadow RD+

- Rider Tuned For Sharp And Silky Shifts - 20% Light Shifting Operation - New Shadow Design With Optimized Slant Angle - Optislick New Shift Cable With New Hyper Low-Friction Coating Technology - Chain Stability Improved - New Shadow Design With Optimized Slant Angle For Stable Gear Position - Efficient Shifting And Smoother Driving - Efficient Pulley Teeth Design - Increased Traction Range For Long-Travel And Active Rear Suspension - Series : SLX: SLX - Maximum Sprocket : 42T(2x11-speed) or 46T(1x11-speed) - Minimum Sprocket : 11T: 34-38T - Front Difference : 10T: 48.8 - Total Capacity : 41T: 66-69 - Average Weight : 323g: 145.6g

Designed with the attention to detail and performance levels demanded of Campagnolo by World Tour cyclists, the Centaur is accurate and fast – perfect for long rides. Inheriting top-of-the-range technologies from Revolution 11+ groupsets, the Centaur offers similar performance to professional components. The longer front connecting rod and the carefully designed one-piece steel cage ensure precise and reliable shifting, with minimal effort required to move from the little ring to the big ring. - Long lever arm creates additional torque for improved shifting - One piece steel cage shaped identically to Super Record for similar performance - Shaped outer semi-cage to improve downshifting speed - New rod design allows for higher shifting forces with less rider effort - Drivetrain Speeds: 11 - Double or Triple: Double - Derailleur Capacity: 16 - Front Derailleur Cable Pull: Bottom Pull - Front Derailleur Clamp: Braze-on - Max Ring (teeth): 55 - Weight: 103 grams - Front Der/Shifter Compatibility: Campy Centaur/Potenza/Chorus/Record/Super Record 2015+

SRAM's GX 2x10 rear derailleur provides incredible shifting speed and precision. Exact Actuation technology eliminates slop and shifting variation. Roller Bearing Clutch technology delivers maximum drivetrain stability—even through the most punishing terrain. And with Cage Lock technology, wheel removal and installation are easier than ever.